I think you should look up Speed Tech, DSE or any of the suspension vendors on this forum. They can give you all of the options and pros and cons for alot of different set ups. There is a number of options for Ford and GM cars all the wat to complete replacement chassis for full frame cars from GM. It is entirely possible to set up old muscle cars to be competitive with just about anything else out there.
I think it's just a matter of what you want.
God luck!